Lamp

ABSTRACT

A lamp having a bulb fixed in the housing and a moving socket engaging pin spring loaded to an extended position. A housing with an inner insulating sleeve molded in place in an outer metal sleeve with a cup-shaped conductor pin retained by the housing and receiving a spring welded to a bulb lead, with the springbulb lead connection encapsulated and with the bulb cemented in the housing with the other lead spot welded to the outer sleeve.

Inn 3,784,867

1 1 Jan.8, 1974 United States Patent [1 1 Dupree 313/113 Michel et313/318 X Kawate 313/318 Jacobs 313/318 68 8 6365 99,99 wmww 0400 27 0 7942 83004 2 3222 1 1 LAMP [75] Inventor: James N. Dupree, Los Angeles,

Calif.

[73] Assignee:

[22] Filed:

Dupree, Inc., South El Monte, Calif.

' Primary ExaminerRud0lph V. Rolinec Oct. 6, 1972 [21] Appl. No.:295,669

Assistant ExaminerSaxfield C hatmon, Jr. AttorneyFord W. Harris, Jr. etal.

[57] ABSTRACT A lamp having a bulb fixed in the housing and a movingsocket engaging pin spring loaded to an extended position. A housingwith an inner insulatin g sleeve h a cupg and re- 0 0 5 0 N &2 0 33 B 5I33 5M2 Jl. 32 H m .3 "Q "m3 mh c an we us I. 00 d ..l Mk .[F 1.1. 18 55ll molded in place in an outer metal sleeve wit shaped conductor pinretained by the housin ceiving a spring welded to a bulb lead, with thespringbulb lead connection encapsulated and with the bulb cemented inthe housing with the other lead spot 313/318 welded to the outer sleeve.313/318 313/318 X 2 Claims, 2 Drawing Figures S m m W N mm m m A P n .aEwm 6 Ban mw e DO rT ao kSDLF e E087 T73.4 www U994 035 359 l 019 33 rl322 LAMP This invention relates to lamps or light bulbs adapted to beremovably mounted in sockets and in particular,

to a new and improved lamp which may be directly substituted for thelamp shown in the US. Pat. to Dupree No. 3,530,330.

The aforementioned Dupree patent discloses a lamp having a bulb fixed ina housing and a pin movable in the housing, with a spring urging the pinto an outward position. The lamp is intended for use with a sockethaving a fixed center contact with the force for maintaining theelectrical contacts being provided by the spring within the lamp.

The prior art lamp has been satisfactory in meeting some of the problemsencountered in the use of lamps and sockets, particularly small sizelamps intended for installation in positions with limited access forsocket maintenance and repair. However some problems have beenencountered in quantity high production manufacture of the lamps,particularly the very small lamps which may be in the order of 3/32 inchdiameter and one-half inch long. Accordingly it is an object of thepresent invention to provide a new and improved spring-loaded lamp and anew and improved process of making such lamps. It is a particular objectof the invention to provide a lamp housing having an inner insulatingsleeve molded in place in an outer metal sleeve. A further object is toprovide such a lamp with a cupshaped conductor pin sliding within thehousing and receiving the spring in the pin cup.A particular object ofthe invention is to provde a new and improved springbulb lead connectionwith a closed turn spring and an encapsulated joint. One additionalobject of the invention is to provide a new and improved mechanical andelectrical connection between the bulb and housing for holding the bulbin place and making an electrical connection to the housing.

Other objects, advantages, features and results will more fully appearin the course of the following de scription.

In the drawing:

FIG. 1 is a sectional view ofa partially assembled lamp andincorporating the presently preferred embodiment of the invention; and-FIG. 2 is a view similar to that of FIG. 1 showing the lamp completelyassembled. l

The lamp includes a bulb with leads 11 and 12, a spring 13, a conductorpin 14, and a housing 15 with an outer metal sleeve 16 and an innerinsulating sleeve 17. l

The housing outer sleeve 16 preferably is drawn from a metal sheet,typically brass sheet, into a sleeve or tubular configuration. Thesleeve 16 has an upper portion 20 for receiving the bulb 10 andterminates in a flange 21. The sleeve 16 also has a lower portion 22 forreceiving the inner sleeve, with opposed circular projections or knobs24 for engaging corresponding passageways in the socket, such as thatshown in the aforementioned US. Pat. No. 3,530,330. An inwardly turnedflange 25 at the lower end of the outer sleeve 16 providesengagementwith the inner sleeve 17.

The inner sleeve 17 is formed of an electrical insulating material andis molded in place in the outer sleeve 16, with interengagement of theinner and outer sleeves at the knobs 24 and flange 25 locking the twopieces.

together. The inner sleeve 17 has a zone 26 for receiving the conductorpin 14, with a shoulder 27 for limiting movement of the pin, and anopening 28 for receiving the tip 29 of the pin 14.

- The conductor pin 14 has a cup 33 for receiving the spring 13 with thetip 29 depending from the cup. The pin preferably is made by drawingfrom a metal sheet producing the cup and tip in one piece in amulti-stage eyelet machine, providing high speed and high volumeproduction for reduced cost.

The lower end of the spring 13 rests in the cup 33 of the pin 14,preferably with a slight interference fit for better electrical contact.A closed turn 34- is provided at the upper end of the spring 13, withthe tip 35 projecting upward and spot welded to the bulb lead 11. Thebulb lead 12 is bent upward alongside the bulb 10.

After the lead 12 has been shaped and the spring has been connected tothe lead 11, the space between the bulb l0 and the closed turn 34 of thelamp is filled or encapsulated with a potting material 37, typically aconventional epoxy potting compound. The potting material is introducedinto the very small space by a hypodermic needle and the closed turn 34of the spring functions to prevent movement of the potting materialalong the spring, which would occur by capillary action with aconventional open turn spring. After curing, the encapsulated joint 37provides the mechanical strength for the connection betweenthe bulb andspring, relieving the spot welded electrical connection of themechanical stress.

Next, a band of cement, typically a conventional epoxy cement, isapplied around the bulb l0 and lead 12, the spring is inserted into thecup of the conductor pin, the pin is slid into the zone 26 of the innersleeve, with the cup engaging the shoulder 27, as seen in FIG. 2, andthe bulb is inserted to the position shown in FIG. 2. The bulb andhousing are maintained in this position while the cement hardens, afterwhich the end 36 of the lead 12 is bent outward and connected to theflange 21 of the housing by spot welding at 40. The surplus end of thelead 12 is broken off, completing the assembly of the lamp.

This new and improved lamp permits the use of drawn sheet metal partsfor the housing outer sleeve and for the conductor pin. This isparticularly advantageous with regard to the pm which normally is madeas a machine part and does not incorporate a cup for receiving andretaining the lower end'of the spring. The design also permits moldingthe inner insulating sleeve in place in the outer sleeve, rather thanrequiring the separate manufacture of an insulating sleeve andsubsequent assembly and joining of the two pieces to produce a housing.Further, the design permits the use of spot welded connections forthe'leads in lieu of the conventional soldered connections, with thelamp construction taking the mechanical strain at the electricalconnections.

I claim:

1. In a spring loaded lamp adapted to be mounted in a socket in lockingengagement, the combination of:

a bulb having first and second leads;

a coil spring having a first end welded directly to said first lead andhaving a second free end, said spring having a closed turn adjacent saidfirst lead;

a conductor having a spring receiving cup at one end and a socketcontacting pin at the other end;

a tubular housing comprising interengaging outer metal and innerinsulating sleeves, with said inner sleeve molded in place in said outersleeve and having a central zone terminating in a shoulder for engagingsaid cup and having an opening for said socket pin.

said outer sleeve having an outwardly turned rim and with said bulbpositioned in said outer sleeve with said second lead bent 180 andpositioned between said bulb and outer sleeve, with the second lead endoverlying and welded directly to said rim; and

a solid potting material positioned between said bulb and spring aboutsaid leads and filling said closed turn mechanically supporting saidspring and leads and electrically insulating said leads from each other;

with said conductor in said housing sliding in said zone with saidspring free end in said cup and urging said pn into said housing.

2. A method of making a spring loaded lamp having a bulb fixed in ahousing with a moving conductor pin for contacting a socket, includingthe steps of:

molding an inner insulating sleeve in place in an outer metal sleeve toform a housing; welding one end of a spring directly to a first bulblead; encapsulating the space between the bulb and a closed turn of thespring with a potting material; positioning the bulb and spring and aconductor pin in said housing, with a second bulb lead bent between thebulb and housing and exposed at the bulb end of the outer sleeve of thehousing; cementing the bulb in the housing outer sleeve; and

welding the exposed second lead to the sleeve.

'o iosc b STATES PATIENT. OFFICE CERTIFICATE 0F CGRRECTION Patent No.3,784 8 67 1L Dated Jammy 8, 1974 lnventor(s) b It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

[75] Inventor: "Los Angeles" should be South El Monte-;

and

Column 3, line 17, Claim 1, "pm" should be -pin-- (Claim 8,

line 26 of amendment dated July 6, 1973).

' sighed ami sealed this 1st day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR, C, MARSHALL DANN Attesting Officer Commissioner ofPatents

1. In a spring loaded lamp adapted to be mounted in a socket in lockingengagement, the combination of: a bulb having first and second leads; acoil spring having a first end welded directly to said first lead andhaving a second free end, said spring having a closed turn adjacent saidfirst lead; a conductor having a spring receiving cup at one end and asocket contacting pin at the other end; a tubular housing comprisinginterengaging outer metal and inner insulating sleeves, with said innersleeve molded in place in said outer sleeve and having a central zoneterminating in a shoulder for engaging said cup and having an openingfor said socket pin, said outer sleeve having an outwardly turned rimand with said Bulb positioned in said outer sleeve with said second leadbent 180* and positioned between said bulb and outer sleeve, with thesecond lead end overlying and welded directly to said rim; and a solidpotting material positioned between said bulb and spring about saidleads and filling said closed turn mechanically supporting said springand leads and electrically insulating said leads from each other; withsaid conductor in said housing sliding in said zone with said springfree end in said cup and urging said pn into said housing.
 2. A methodof making a spring loaded lamp having a bulb fixed in a housing with amoving conductor pin for contacting a socket, including the steps of:molding an inner insulating sleeve in place in an outer metal sleeve toform a housing; welding one end of a spring directly to a first bulblead; encapsulating the space between the bulb and a closed turn of thespring with a potting material; positioning the bulb and spring and aconductor pin in said housing, with a second bulb lead bent 180* betweenthe bulb and housing and exposed at the bulb end of the outer sleeve ofthe housing; cementing the bulb in the housing outer sleeve; and weldingthe exposed second lead to the sleeve.